The invention pertains to a multi-layered coated cutting tool and a method for making the same. More particularly, the invention pertains to a nanolayered coated cutting tool and a method for making the same. In this regard, a nanolayered coated cutting tool has a coating scheme that comprises adjacent coating nanolayers having thicknesses of about 100 nanometers or less.
Multi-layered coated cutting tools demonstrate excellent metalcutting properties in certain circumstances. Typically, a multi-layered coated cutting tool comprises a substrate with a plurality of coating layers deposited thereon. In some cases the coating layers comprise a plurality of sets of alternating coating layers. In this regard, U.S. Pat. No. 6,103,357 to Selinder et al. for a MULTILAYERED COATED CUTTING TOOL shows a multi-layered non-repetitive coating scheme in which the layers have a thickness that ranges between 0.1 to 30 nanometers. PCT Patent Application WO98/44163 to Sjxc3x6strand et al. for a MULTILAYERED COATED CUTTING TOOL shows a multi-layered repetitive coating scheme in which each repeat period has a thickness that ranges between 3 and 100 nanometers.
Other exemplary coating schemes comprise multi-layered titanium nitride/titanium aluminum nitride coatings deposited by physical vapor deposition (PVD) techniques. Such coating schemes are described in Hsieh et al., xe2x80x9cDeposition and Characterization of TiAlN and multi-layered TiN/TiAlN coatings using unbalanced magnetron sputteringxe2x80x9d, Surface and Coatings Technology 108-109 (1998) pages 132-137 and Andersen et al., xe2x80x9cDeposition, microstructure and mechanical and tribological properties of magnetron sputtered TiN/TiAlN multilayersxe2x80x9d, Surface and Coatings Technology 123 (2000) pages 219-226.
Even though multi-layered titanium nitride/titanium aluminum nitride coating schemes exist, for a coating to be effective it must possess a certain minimum adhesion to the substrate and it must exhibit a certain minimum hardness. It has always been, and still remains, a goal to improve the adhesion of the coating to the substrate of the coated cutting tool. In addition, it has always been, and still remains, a goal to optimize the hardness of the coated cutting tool. It has always been, and still remains, a goal to improve and optimize the combination of the properties of adhesion and hardness for a coated cutting tool.
It would thus be desirable to provide a coated cutting tool (e.g., a nanolayered coated cutting tool), as well as a method for making the coated cutting tool, wherein the cutting tool possesses improved adhesion and optimized hardness, as well as an improvement in the combination of the adhesion and hardness.
It would also be desirable to provide a metal nitride/metal aluminum nitride coated cutting tool (e.g., a nanolayered titanium nitride/titanium aluminum nitride coated cutting tool), as well as a method for making the coated cutting tool, wherein the cutting tool possesses improved adhesion and optimized hardness, as well as an improvement in the combination of the adhesion and hardness.
It would also be desirable to provide a metal aluminum nitride/metal aluminum carbonitride coated cutting tool (e.g., a nanolayered titanium aluminum nitride/titanium aluminum carbonitride coated cutting tool), as well as a method for making the coated cutting tool, wherein the cutting tool possesses improved adhesion and optimized hardness, as well as an improvement in the combination of the adhesion and hardness.
It would also be desirable to provide a metal nitride/metal aluminum nitride/metal aluminum carbonitride coated cutting tool (e.g., a nanolayered titanium nitride/titanium aluminum nitride/metal aluminum carbonitride coated cutting tool), as well as a method for making the coated cutting tool, wherein the cutting tool possesses improved adhesion and optimized hardness, as well as an improvement in the combination of the adhesion and hardness.
In one form, the invention is a nanolayered coated member that comprises a substrate that has a surface and a coating on the surface of the substrate. The coating comprises a plurality of coating sets of nanolayers wherein a set comprises alternating nanolayers of a nanolayer of a metal nitride (wherein the metal nitride may optionally include carbon and/or silicon) and a nanolayer of a metal aluminum nitride (wherein the metal aluminum nitride may optionally include carbon and/or silicon). The coating includes a bonding region and an outer region. The bonding region comprises a plurality of the coating sets wherein the thickness of a coating set generally increases as one moves away from the surface of the substrate. The outer region comprises a plurality of the coating sets. The metal may comprise titanium, niobium, hafnium, vanadium, tantalum, zirconium and/or chromium alone or in combination with each other or in combination with other metals including aluminum in the metal nitride layer so long as the composition of the metal nitride layer differs from that of the metal aluminum nitride layer.
In another form, the invention is a nanolayered coated member that comprises a substrate that has a surface and a coating on the surface of the substrate. The coating comprises a plurality of coating sets of nanolayers wherein a set comprises alternating nanolayers of a nanolayer of a metal aluminum nitride (wherein the metal aluminum nitride may optionally include carbon and/or silicon) and a nanolayer of a metal aluminum carbonitride (wherein the metal aluminum carbonitride may optionally include silicon). The coating includes a bonding region and an outer region. The bonding region comprises a plurality of the coating sets wherein the thickness of a coating set generally increases as one moves away from the surface of the substrate. The outer region comprises a plurality of the coating sets. The metal may comprise titanium, niobium, hafnium, vanadium, tantalum, zirconium and/or chromium alone or in combination with each other or in combination with other metals.
In yet another form, the invention is a nanolayered coated member that comprises a substrate that has a surface and a coating on the surface of the substrate. The coating comprises a plurality of coating sets of nanolayers wherein a set comprises alternating nanolayers of a nanolayer of a metal nitride (wherein the metal nitride may optionally include carbon and/or silicon), a nanolayer of a metal aluminum nitride (wherein the metal aluminum nitride may optionally include carbon and/or silicon), and a nanolayer of a metal aluminum carbonitride (wherein the metal aluminum carbonitride may optionally include silicon). The coating includes a bonding region and an outer region. The bonding region comprises a plurality of the coating sets wherein the thickness of a coating set generally increases as one moves away from the surface of the substrate. The outer region comprises a plurality of the coating sets. The metal may comprise titanium, niobium, hafnium, vanadium, tantalum, zirconium and/or chromium alone or in combination with each other or in combination with other metals including aluminum in the metal nitride layer so long as the composition of the metal nitride layer differs from that of the metal aluminum nitride layer and metal aluminum carbonitride layer.
In still another form thereof, the invention is a process for making a nanolayered coated member, the process comprising the steps of: providing a substrate having a surface; providing a metal target (wherein the metal target may optionally include carbon and/or silicon); providing a metal-aluminum target (wherein the metal-aluminum target may optionally include carbon and/or silicon); rotating a substrate between the metal target and the metal-aluminum target; supplying electrical power at a first level of electrical power to the metal target; supplying electrical power at the first level to the metal-aluminum target; depositing a coating comprising coating sets of alternating nanolayers on the surface of the substrate; changing the deposition rate of the alternating nanolayers over a selected period of time during which electrical power supplied to the metal target changes from the first level to a second level; and controlling the deposition rate of the alternating nanolayers for a period of time after the electrical power reaches the second level. The metal may comprise titanium, niobium, hafnium, vanadium, tantalum, zirconium and/or chromium alone or in combination with each other or in combination with other metals including aluminum in the metal target so long as the composition of the metal target differs from that of the metal-aluminum target.
In still another form thereof, the invention is a process for making a nanolayered coated member, the process comprising the steps of: providing a substrate having a surface; providing a metal-aluminum target (wherein the metal-aluminum target may optionally include carbon and/or silicon); providing a metal-aluminum-carbon target (wherein the metal-aluminum-carbon target may optionally include silicon); rotating a substrate between the metal-aluminum target and the metal-aluminum-carbon target; supplying electrical power at a first level to the metal-aluminum target; supplying electrical power at the first level to the metal-aluminum-carbon target; depositing a coating comprising coating sets of alternating nanolayers on the surface of the substrate; changing the deposition rate of the alternating nanolayers over a selected period of time during which electrical power supplied to the metal-aluminum target and the metal-aluminum-carbon target changes from the first level to a second level; and controlling the deposition rate of the alternating nanolayers for a period of time after the electrical power reaches the second level. The metal may comprise titanium, niobium, hafnium, vanadium, tantalum, zirconium and/or chromium alone or in combination with each other or in combination with other metals.
In still another form thereof, the invention is a process for making a nanolayered coated member, the process comprising the steps of: providing a substrate having a surface; providing a metal target (wherein the metal target may optionally include carbon and/or silicon); providing a metal-aluminum target (wherein the metal-aluminum target may optionally include carbon and/or silicon); providing a metal-aluminum-carbon target (wherein the metal-aluminum-carbon target may optionally include silicon); rotating a substrate between the metal target and the metal-aluminum target and the metal-aluminum-carbon target; supplying electrical power at a first level to the metal target; supplying electrical power at the first level to the metal-aluminum target; supplying electrical power at the first level to the metal-aluminum-carbon target; depositing a coating comprising coating sets of alternating nanolayers on the surface of the substrate; changing the deposition rate of the alternating nanolayers over a selected period of time during which electrical power supplied to the metal target and to the metal-aluminum target and to the metal-aluminum-carbon target changes from the first level to a second level; and controlling the deposition rate of the alternating nanolayers for a period of time after the electrical power reaches the second level. The metal may comprise titanium, niobium, hafnium, vanadium, tantalum, zirconium and/or chromium alone or in combination with each other or in combination with other metals including aluminum in the metal target so long as the composition of the metal target differs from that of the metal-aluminum target and the metal-aluminum-carbon target.